In this composite character, the body of a cart is combined with two counting rods (the numeral two). The numeral indicates the relative size of the cart. Hence, Mahadevan's sign number 329 is an
ideograph for a medium-sized cart.

Comment:

Unfortunately, none of the extant Indus inscriptions give us the dimensions for the body of this cart. However, we can infer that it was two-thirds the size of a large cart, or four Indus units
in length.